If you’re lucky enough to have a greenhouse, polytunnel or even a plastic cloche then one way to get a jump start on the season is to invest in a soil heating cable. These can be fairly inexpensive to very expensive and come in a range of lengths, so whether you have a large window box or a large veg plot in your garden, there will be one to suit your needs.
To help warm the soil in your outdoor beds without a heating cable, you can use black plastic sheeting – not only will this help warm the soil but it will create a perfectly warm and moist environment for weed seeds to germinate. And this is a good thing you ask? Well yes it is, and here’s why -although the seeds don’t need light to germinate the seedlings do in order to grow. With the black plastic cutting out the light they’ll soon run out of energy and die. What you end up with is a sterile bed ready for planting without having to dig or weed. Remember to cover outdoor beds early enough to let the weeds germinate and die before your hardened seedlings are ready to be transplanted – around two to four weeks should be enough depending on the weed burden in your plot and the time of year.
Although heating cables are brilliant for using directly in the soil they can also be used to make heated propagation tables. Again these can be as big or small as your space and budget will allow and will help you to get even further ahead of the season. At The Edible Garden, we’ve built our heated propagation tables out of 8’x4’ sheets of ply, a few bits of scrap wood and some spare straw bales. By the time your seedlings are big enough to be hardened off the soil temperature outside should be high enough for transplanting – the trick is not to start them off too early.
Once your bed is ready for planting it’s crucial that you don’t do any more cultivation or turning of the soil as this will bring up dormant seeds to the surface and you’ll either have to weed the bed or cover with the black plastic again for another two weeks!